In treating vascular defects such as aneurysms and fistulas, which commonly occur in the neurovasculature, a microcatheter is navigated through the patient's vasculature until a distal end of the microcatheter is adjacent the defect. An embolic material is then delivered through the microcatheter and into the vascular defect, to thereby fill and seal-off the defect. However, because vascular defects like aneurysms and fistulas often have irregularly shaped and asymmetrical volumes, it is difficult to accurately and completely fill the defect with embolic coils, balloons or other embolic devices, which are typically symmetrically shaped. Although liquid embolic materials tend to fill irregularly shaped and asymmetrical volumes more precisely and completely, liquid embolic materials are often difficult to deliver through a microcatheter and are often difficult to contain within the defect. Accordingly, there is a substantial need for an embolic material and delivery system that is capable of filling an asymmetrical and irregularly shaped vascular defect, that is easy to deliver with a microcatheter, and that is easy to contain within the defect.
There is also an ongoing need for improved embolic balloons and associated delivery systems. In particular, there is a need for detachable embolic balloons that may be easily delivered and maintained in the vascular defect so as to not protrude into the native vascular lumen.